1. Field of the Invention
Example embodiments relate to a voltage generator and a nonvolatile memory device including the same and, more particularly, to a voltage generator including pump circuits.
2. Description of the Related Art
A nonvolatile memory device includes a memory cell array for storing data and a variety of circuits for storing data in the memory cell array or for reading data stored in the memory cell array. The circuits may include a controller for generating various control signals, a voltage generator for generating voltages necessary for a program, read, or erase operation in response to the control signals of the controller, a row decoder for selecting one of a plurality of cell blocks included in the memory cell array and transferring the voltages from the voltage generator to the selected cell block, a column selector for selecting a column in response to the control signals of the controller, and a page buffer group.
The voltage generator generates voltages necessary for the program, read, or erase operation and transfers the voltages to the row decoder. In particular, in the case of the program operation, the voltage generator requires a plurality of pump circuits for generating high voltages because the high voltages of 15 V to 30 V are required. Furthermore, not only the high voltages, but also low voltages are required because various levels of voltages are required according to the operation in the semiconductor device.
As described above, the various levels of voltages are generated by the voltage generator. The voltage generator drives all the pump circuits for generating the high voltage in response to clock signals generated by an oscillator. However, even when the low voltage is generated, all the pump circuits are operated in response to the clock signals, leading to unnecessary current consumption.